Here’s a fun fact for ya: MLB games are nine innings. Yep, I’d keep that one safely tucked away in the noggin for your next bar trivia night … might come in handy.

Alright so everyone knows that. But what percent of games actually play all nine? Well, any game where the home team is up after eight-and-a-half doesn’t, and given that home teams win more often than not, that number is probably around 50%, if not more.

So when betting on an over, keep in mind that about half the time you’re betting on 17 half-innings of play, not 18.

That raises the question: How can we ensure that we get all 18? Simple. We focus only on games where we think the visiting team will be up after 8.5 innings. In other words, games where the home team is a big underdog.

The bigger a favorite the visiting team is, the likelier it is that the bottom of the ninth will be played.

Using BetLabs, I ran a test to see how the over performed in games that fit this theory. Sure enough, when the home team is listed at +200 or higher, the over has gone 104-67-10, winning 30.9 units for a 17.1% return on investment since 2005.

And since I don’t like fading sharp action, I narrowed this system down into cases where the total did not fall from its opening number. That resulted in an 86-51-8 record for 29.6 units and a 20.4% ROI.

I’m not going to try to claim that the win rate is completely due to the edge gained by playing the bottom of the ninth, but for what it’s worth, I ran the opposite test a few months back and got equally intriguing results.

When the home team is a big favorite (-300 or higher), the under has gone 73-54-4 since 2005 (again assuming that the total did not drop). So there’s clearly something here.

With all that said, the White Sox are a +234 home favorite this evening against the Yankees. Assuming the total remains at 8.5, I’ll be betting on runs.

The Bet: Over 8.5

Editor’s note: The opinion on this game is from the individual writer and is based on his research, analysis and perspective. It is independent of, and may not always match with, the algorithm-driven Best Bets from Sports Insights.